The reduced thrust take-off burns more fuel but supposedly saves money overall by reducing maintenence cost over the life of the engine. I suppose that if you keep the engine in "better" condition by using reduced thrust take-offs then the engine will be more efficient in cruise for a longer time so you recover the extra fuel costs from the reduced power take-off.
Interestingly, most of the benefits of reduced thrust on maintenence costs are achieved at a fairly small thrust reduction because the stress on the engine peaks rapidly at t/o power settings. A big thrust reduction does not have a proportional big saving in engine wear.
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